Winding apparatus for an electric clock



June 4, 1968 -w, EARLEYWINEJR 3,386,237

' WINDING APPARATUS FOR AN'ELECTRIC CLOCK' Filed Feb. 14, 1966 A 4161 8] 2% fal/f/al/ik i United States Patent 3,386,237 WINDING APPARATUS FOR AN ELECTRIC CLOCK Aubrey W. Earleywine, Jr., Springfield, Ill., assignor to Stewart-Warner Corporation, Chicago, EL, a corporation of Virginia Filed Feb. 14, 1966, Ser. No. 527,315 11 Claims. (Cl. 58-41) This invention relates in general to an improved armature construction for use in electrically operated car clocks.

In electrically driven car clocks, an electromagnet is periodically energized to wind the main spring, which drives the clock. The magnet attracts an associated armature, pivoted on one axis to in turn rotate an inertia weight pivoted on another axis. Only a component of the force moving the armature is available, therefore, for moving the inertia weight to wind the spring.

It is therefore one object of the present invention to rotate the inertia weight and armature of a clock about a common axis to ensure the maximum transmission of force therebetween. Rotation of the armature in one direction is terminated when it strikes the core of the electromagnet, and on deener-gization of the magnet, the armature is rotated under spring tension until a stop is engaged. The metal to metal contact of the armature against the core or the stop gives rise to objectionable noise.

It is therefore another object of the present invention to eliminate the aforedescribed source of objectionable noises in electrically driven car clocks or the like.

Other objects of the present invention include improvements in the magnet circuit and armature control apparatus of an electrically driven car clock and a more economical car clock construction.

Still other objects and features of this invention will become apparent on examination of the following specification, claims and drawings wherein:

FIG. 1 is a side elevational view of a portion of a car clock assembly utilizing the principles of the present invention;

FIG. 2 is a top elevational view taken of the clock portion shown in FIG. 1 with the front plate omitted;

FIG. 3 is a sectional view taken along the line 3-3 in FIG. 2; and

FIG. 4 is a sectional view of the inertia weight taken along the line 44 illustrating a recess for relieving stresses on the main spring during winding.

In FIGS. 1 and 2 a portion of an electrically operated car clock assembly is indicated generally by the reference character 10. The assembly comprises a back plate 12 and a frame plate 14 secured together in abutting relationship. One end of a drive shaft 16 is pivotally supported in the back plate 12, and the other end of the shaft extends through an opening in a front plate 18 for pivotal engagement in a tang 20 on the front plate. The drive shaft supports a drive assembly 22.

The drive assembly 22 comprises a drive wheel 24 which drives the pinion gear 26 of a 1 r.p.m. wheel, for example, to move the clock hands at a rate controlled by a conventional clock escapement in any well known manner. The drive wheel 24 is powered by a main spring 28 having one end connected to a tab 30 on the back plate 12 and its other end connected to a tab 32 on an inertia weight 34 of die cast metal, for example.

The inertia weight 34 is rotatably carried on shaft 16 and a spring clutch 36 transmits the movement of the inertia weight to a bushing 38, when the inertia weight is driven in a counterclockwise direction as seen in FIG. 2 by spring 28. The bushing 38 is press fit on shaft 16 and transmits movement from the inertia weight through shaft 16 to the drive wheel 24 and the clock hands. The spring clutch 36 permits the inertia weight 34 to be driven in the opposite or clockwise direction as seen in FIG. 2 Without rotating the bushing 38, shaft 16, and drive wheel 24.

An electromagnet 40 is provided for driving the inertia weight 34 in the opposite or clockwise direction, as seen in FIG. 2, to wind spring 28. The electromagnet 40 has a coil which encircles a core 42. The core 42 projects thereabove to form a pole piece for one end of an elongate armature 44. A residual post or pole piece 46 is provided adjacent the other end of the armature 40 and both pole pieces 42 and 46 are cut away adjacent the path traversed by the armature in an arc of size corresponding to the armature end faces and adjacent the path of the end face. In addition the pole pieces also serve to support and properly space the front plate 18 relative to the back plate 12. A magnetic circuit is extended between pole pieces 42 and 46 by the frame plate 14, which is of magnetic material such as soft iron and which is likewise held by the pole pieces.

The armature 44 is press fit on a bushing 48 rotatably carried by shaft 16. An electrical insulating contact arm 50 of a material such as nylon is fixed to bushing 48 below armature 44. The arm 50 has a tab 52 thereon, which projects into an opening 54 in the armature so that the armature 44 and contact arm 50 rotate together about shaft 16.

A contact 58 is carried on the end of a cantilever projection 60 of the contact arm for engagement with contact 62. Contact 62 is carried on a projection 64 of the inertia weight 34, and it engages contact 58 when the main spring 28 has driven the inertia weight 34 to one limit position. A return spring 66, which is fastened at one end to contact 58 and is looped about the hub of arm 50, serves to bias the armature 44 in a counterclockwise direction, as seen in FIG. 2. A stop arm 68 integrally formed on the contact arm 50 engages the electromagnet 40 to maintain the contact 58 in one limit position when magnet 40 is deenergized.

To energize the electromagnet 40 a circuit is extended from a source of direct current such as from one terminal of the car battery to a tab 70, and from the tab 70 to one terminal of the magnet coil. The other terminal of magnet 40 is soldered to the end of spring 66 opposite contact 58 and when contact 58 engages contact 62, the circuit is extended from tab 70 through magnet 40 to the weight 34. An L-shaped wiper arm 72 having a tab fastened to plate 12, extends above the plate and is engaged with the wall of a recess 64 in the outer periphery of the inertia weight to extend the circuit to the plates 12 and 14 which are connected to the ground terminal of the battery in any well known manner.

The end of spring 66, opposite contact 58, is secured by means of an integrally formed spring clip 74 to a post 76 of electrically insulated material and. the corresponding terminal of coil 40 is soldered to clip 74. Clip 74 is formed in a generally upwardly opening U-shape having a back leg 78 and side legs 80 and '82. Side leg 80 is extended in several bends to provide a reverse leg 84 spaced from leg 78 and terminating in a depending portion 86.

The clip 74 is engaged in an opening 88 in post 76 with the two legs 78 and 84 being under tension against the respective walls of the opening 88 and the two side legs 80 and 82 adjacent opposite outer walls of the post 76. The opening 86 has an elongate portion adjacent one end through which the legs 80 and 84 may pass on assembly to the post 76. The clip 74 is then moved into the narrow portion of opening 88 with which it is naturally aligned, whereafter it is retained in that portion of opening 88.

The electrically insulated post 76 has an integrally formed platform portion 90 at its bottom end in which a central opening is provided. The tab 70 is staked to a stud 91 in the opening. The stud 91 may be used for an electrical connection to tab 76 from a lead external to the clock housing. The platform 26 has a recess 92 of generally U-shape along three sides thereof for receiving the edge of a correspondingly shaped opening in the plate 14. When the plate 12 is fixed to the plate 14, one side of the opening in the plate 12 abuts the flat side of the platform 90 to hold the post 7'6 and tab '70 in position.

During operation of the clock the main spring 23 pulls the inertia weight 34 and the drive wheel 24 through the spring clutch 36 to one limit position. The clock hands are driven by the wheel 24. The contact 62 engages contact 58 when the inertia weight reaches the limit position. The electromagnet 46 is therefore energized and the armature 44 is attracted to the pole pieces 42 and 46. Since the pole pieces are spaced adjacent but not in the path of travel of the armature, the armature swings into alignment therewith without striking or otherwise engaging the pole pieces, thereby avoiding metal to metal contact.

The contact arm 50 is rotated with the armature 44 and swings the inertia weight 34 about the same axis for tensing the main spring 28. The force is transmitted through the contacts 58 and 62 in the direction of movement to provide a maximum transmission. The clutch 36 permits the inertia weight 34 to rotate free of the drive wheel 24. As the inertia weight moves it tenses or winds the main spring 28. An arcuate recess 94 of progressively increasing depth initiated adjacent the point of tangency and along the outer surface of weight 34 adjacent the bottom edge, swings into alignment with spring 28. This relieves stresses on the spring and maintains the spring properly aligned. The armature rotates into alignment with the pole pieces 42 and 46 and terminates move ment, while the inertia weight 34 of course travels a short distance further, thereby opening the contacts 58 and 62 to deenergize the electromagnet 40.

The armature 44, contact arm 50 and contact 58 now return to their normal position under the tension of spring 66 without engaging a metal surface, while the inertia weight 34 drives the clock hands under the power of the tensed main spring 28 and at a rate determined by the escapement.

The foregoing constitutes a description of an improvement in car clocks whose inventive concepts are set forth in the accompanying claims.

What is claimed is:

1. An improvement in a car clock of the type ncluding an electromagnet for rotating an inertia weight in one direction on energization of said electromagnet to wind at mainspring arranged to drive the clock hands, the improvement comprising an armature for said magnet, means mounting said armature for rotation independent of said inertia weight and coaxial therewith, and means rotatable with said armature in response to energization of said coil for rotating said inertia weight in said one direction about said axis with the major component of the force generated on movement of said armature transmitted to said inertia weight through an arc coaxial with said axis.

2. In the improvement claimed in claim 1, a pair of magnetically susceptible spaced apart pole pieces for said armature with one of said pole pieces forming a core for said electromagnet and both of said pole pieces located adjacent but spaced from the are described on rotation of said armature to prevent engagement between said armature and pole pieces.

3. In the improvement claimed in claim 2, a pair of plates spaced and clamped by said pole pieces for supporting said armature and Weight.

4. In the improvement claimed in claim 3, a magnetically susceptible plate between said pole pieces.

5. In the improvement claimed in claim 1, a return sprin for said armature to rotate said armature in said opposite direction on deenergization of said coil, and a stop of plastic material carried by said armature for engaging said magnet in response to rotation of said armature in said opposite direction to provide one limit position for said armature.

6. An improvement in a car clock of the type including an electromagnet for rotating an inertia weight in one direction on energization of said electromagnet to wind a mainspring arranged to rotate said weight in another direction on deenergization of said magnet for operating a drive wheel having a clutch connection to said weight at a rate controlled by an escapement, the improvement comprising an armature for said magnet mounted for coaxial rotation independent of said inertia weight and coaxial therewith, a contact carried by said inertia weight, an electrical contact rotatable by said armature about said axis and positioned to be engaged by said inertia weight contact for energizing said electromagnet in response to said weight being rotated by said spring to a predetermined position, whereafter said armature rotates said contacts and inertia weight about said axis with the force generated by said energized magnet being transmitted from said armature contact to said inertia weight contact along an arc coaxial with said axis.

'7. The improvement claimed in claim 6 in which said main spring is helically wound and extends in an are about said weight with one portion of said spring being tangent to said weight, and said weight has a recess rotated into engagement with said spring adjacent said tangent portion during rotation of said weight in said one direction.

8. The improvement claimed in claim '7 in which said recess is progressively deeper along an are initiated adjacent said tangent portion.

9. An improvement in a car clock of the type including a mainspring for rotating a metal inertia weight having a clutch for connecting said weight to a drive wheel to rotate said drive wheel in one direction at a rate controlled by an escapement, the improvement comprising an electromagnet for energization from a source of direct current potential, an armature mounted for rotation independent of said inertia weight about a common axis, a contact carried by said inertia weight, a wiper arm engaging said inertia weight for extending an electrical connection to said contact through said weight, a contact arm of insulating material mounted for rotation with said armature and having an electrical contact thereon electrically connected to said coil for engagement with said inertia weight contact to energize said coil in response to said inertia weight being rotated to a predetermined position by said spring.

10. An improvement in a car clock of the type including a clock mechanism having mainspring for rotating a metal inertia weight to drive the clock hands in one direction at a rate controlled by an escapement, the improvement comprising a pair of plates for supporting said clock mechanism, a pair of magnetically susceptible pole pieces holding said plates in spaced apart positions, a third plate of magnetically susceptible material fastened to one of said plates and extending between said pole pieces to provide a magnetic circuit therebetween, a coil encircling one of said pole pieces for energization from a source of direct current potential in response to the completion of an electrical circuit to opposite terminals of said coil, an armature mounted for coaxial rotation with said inertia weight in one direction for alignment with said poles pieces in response to the energization of said magnet, a contact carried by said inertia weight, a wiper arm engaging said inertia weight for extending an electrical connection to said contact, a contact arm of insulating material mounted for rotation with said armature and having a contact thereon for engagement with said inertia weight contact on said weight being rotated to one position by said mainspring, a post of insulating material carried -by one of said plates with means thereon for extending one electrical connection to one terminal of said coil, a return spring having one end fixed to said contact arm contact and its other end detachably secured to said post whereby said return spring serves to rotate said armature and contact arm from alignment with said pole pieces on deenergization of said electromagnet to place said contact arm contact in said position, and an electrical connection between the opposite terminal of said electromagnet and said return spring for completing a circuit to said electromagnet on closure of said contacts for rotating said armature and inertia weight to wind said mainspring.

11. An improvement in a car clock of the type including a mainspring rotating an inertia weight pivotally supported between a pair of plates and having a clutch for driving the hands of said clock in one direction at a rate controlled by an escapement, the improvement comprising an electromagnet for energization from a source of direct current potential, an armature mounted for rotating said inertia weight to wind said mainspring on energization of said coil, means for energizing said electromagnet to rotate said Weight in response to said inertia weight reaching a predetermined position, a pair of pole pieces for attracting said armature with one of said pole pieces passing through said electromagnet and both of said pole pieces serving to fasten and space said plates, and means for extending a magnetic circuit between said pole pieces.

References Cited UNITED STATES PATENTS 2,715,812 10/1955 Grether et a1. 58-41 RICHARD B. WILKINSON, Primary Examiner.

E. C. SIMMONS, Assistant Examiner. 

1. AN IMPROVEMENT IN A CAR CLOCK OF THE TYPE INCLUDING AN ELECTROMAGNET FOR ROTATING AN INERTIA WEIGHT IN ONE DIRECTION ON ENERGIZATION OF SAID ELECTROMAGNET TO WIND A MAINSPRING ARRANGED TO DRIVE THE CLOCK HANDS, THE IMPROVEMENT COMPRISING AN ARMATURE FOR SAID MAGNET, MEANS MOUNTING SAID ARMATURE FOR ROTATION INDEPENDENT OF SAID INERTIA WEIGHT AND COAXIAL THEREWITH, AND MEANS 